• 제목, 요약, 키워드: synchronous generator

검색결과 540건 처리시간 0.039초

내연기관 구동 비상용 브러시리스형 동기발전기의 과도특성 개선 (Improvement of Transient Characteristics of Brush-less Type Synchronous Generator for Emergency Driven by Internal-Combustion Engine)

  • 안영주
    • 전기학회논문지P
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    • v.65 no.4
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    • pp.268-272
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    • 2016
  • A brush-less type synchronous generator is driven by an internal-combustion engine that is used for emergency source. This kind of generator has to maintain output voltage in a range of some degree under the abrupt load irregular conditions such as a full load trip. This paper suggests a suppression method of increasing the output voltage over the rating. Automatic voltage regulator detects excessive rising of output voltage of the generator and supplies the signals to a switch installed in the rotating exciter through the photo-coupler. The current of main field rapidly decreases by additional resistor of the main filed circuit. Therefore, the output voltage of the generator is maintained effectively. The experimental results verified that the excessive value of the output voltage is limited in the range of 7% of the rated voltage.

동기발전기 여자시스템용 고주파 PWM 컨버터 설계 (Design of a High Frequency PWM Converter for Synchronous Generator Excitation System)

  • 장수진;류동균;원충연;이진국;배기훈;김수석
    • 전력전자학회:학술대회논문집
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    • pp.515-518
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    • 2002
  • A synchronous generator is equipped with an automatic voltage regulator(AVR), which is responsible for keeping the output voltage constant under normal operating conditions at various levels. The output voltage of Synchronous Generator is regulated constantly by field voltage control in excitation system. High frequency PWM converter (Buck converter) type excitation system for synchronous generator that can sustain prefer output voltage level even at the fault condition happened. The proper operation of the proposed excitation system was verified through the simulations and the experiments.

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Design and Analysis of Permanent Magnet Synchronous Generator Considering Magnetically Coupled Turbine-Rotor System

  • Kim, Byung-Ok;Choi, Bum-Seog;Kim, Jeong-Man;Cho, Han-Wook
    • Journal of Electrical Engineering and Technology
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    • v.10 no.3
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    • pp.1002-1006
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    • 2015
  • In this paper, design and analysis of permanent magnet synchronous generator for ocean thermal energy conversion (OTEC) considering magnetically coupled turbine-rotor system is discussed. In particular, the rotor dynamics considering bearing span and journal shaft diameter is highlighted. The two topologies of permanent magnet synchronous generator with magnetic coupling are employed for comparison of computed rotor dynamics and generating characteristics. The analysis results show that the critical speed of the turbine-rotor system is higher when the rotor is coupled by magnetically coupling. Finally, the experimental results confirmed the validity of the proposed design and analysis scheme and successful development.

Power Management of Open Winding PM Synchronous Generator for Unbalanced Voltage Conditions

  • EL-Bardawil, Ashraf;Moussa, Mona Fouad
    • Journal of Power Electronics
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    • v.16 no.6
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    • pp.2192-2201
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    • 2016
  • Wind energy is currently the fastest-growing electricity source worldwide. The cost efficiency of wind generators must be high because these generators have to compete with other energy sources. In this paper, a system that utilizes an open-winding permanent-magnet synchronous generator is studied for wind-energy generation. The proposed system controls generated power through an auxiliary voltage source inverter. The VA rating of the auxiliary inverter is only a fraction of the system-rated power. An adjusted control system, which consists of two main parts, is implemented to control the generator power and the grid-side converter. This paper introduces a study on the effect of unbalanced voltages for the wind-generation system. The proposed system is designed and simulated using MATLAB/Simulink software. Theoretical and experimental results verify the validity of the proposed system to achieve the power management requirements for balanced and unbalanced voltage conditions of the grid.

피드포워드 제어기를 사용한 동기발전기의 과도특성 개선 (Improvement of Transient Performance of Synchronous Generator using Feedforward Controller)

  • 안영주
    • 전기학회논문지P
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    • v.67 no.2
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    • pp.57-62
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    • 2018
  • A brush-less type synchronous generator driven by an internal-combustion engine is used for emergency electric source. These types of generators have to maintain a certain range of output voltage even under the sudden load change conditions such as full load application and removal. This paper describes a method for suppressing the output voltage of a synchronous generator that operates excessively when the load fluctuates. The method used in this paper is a feedforward control method in which the main voltage control consists of a feedback loop using a typical PID controller and the load current is detected as a disturbance element and compensated directly. A feedforward system is constructed in which the load current is regarded as disturbance, and the appropriate feedforward controller configuration and parameters are found through simulation. Finally, it can be seen through the experiment that the feedforward control is performed properly. It can be seen that the generator terminal voltage is recovered to the steady state in a short period of time as compared with the existing PID control method even when the entire load of the generator is changed.

풍력발전시스템이 연계된 계통의 과도상태해석 (Transient State Analysis of Network Connected to Wind Generation System)

  • 김세호
    • 한국태양에너지학회 논문집
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    • v.23 no.3
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    • pp.29-35
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    • 2003
  • Generator for wind power can be either synchronous or asynchronous (induction) types. Induction and synchronous generators behave in a different way when subjected to severe faults. Induction generators does not have an angle stability limit and short circuit in the neighborhood of an Induction generator causes the demagnetization of the machine when the fault is cleared, the voltage raises slowly, while the grid contributes with reactive power to the generator and the magnetic flux recovers. On the other hand in the synchronous generators the recovery of the voltage is immediate, since the excitation of the rotor angle comes from an independent circuit. This paper shows the result of the transient state analysis in the network connected to wind generation system Several case studies have been conducted to determine the effect of the clearing time of a fault on the network stability. It has been found that the critical clearing time can be as low as 61ms in the case of induction generator compared to 370ms in the case of synchronous generator.

혼합형 디지털 자동 전압 조정 장치를 이용한 선박용 동기발전기의 출력전압제어 (Voltage Control of a Synchronous Generator for Ship using a Compound Type Digital AVR)

  • 박상훈;이상석;유재성;이수원;원충연
    • 전기학회논문지P
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    • v.58 no.4
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    • pp.397-403
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    • 2009
  • In this paper, an exciter current control of a synchronous generator for ships using a compound type digital automatic voltage regulator (DVAR) in order to provide a constant output voltage of the generator is presented. The compound type DAVR is composed of a controller part to adjust output voltage and an power source unit to supply power to the exciter. The controller part, which generates the PWM switching pattern via the PI controller, drives a power MOSFET for bypass to limit the SG's exciter current. The power source unit part is parallel connected to an output terminal of the generator through a reactor and a power CT. The residual magnetic flux of SG provides exciter current to the exciter through the reactor during the initial running or no load state and load current supplies field current to the exciter through the power CT during loading state. This paper confirmed an experiment to verify the validity of compound type DAVR system for controlling output voltage of synchronous generator.

화력발전소의 동기발전기 여자기 성능개선 연구 (The Improvement of the Synchronous Genertor Excitor performance for Power Fire Plant)

  • 홍현문
    • 대한전기학회:학술대회논문집
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    • pp.998-998
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    • 2008
  • It is difficult to find for analysis solution of the synchronous generator exciter system. Recently, it had good performance UPS converter system using CRA method. The single converter of synchronous generator excitor system under considerations : (i) the overall system shall keep very low AC-voltage tracking error as well as no phase delay over different load condition, and (ii) the digital controller shall be employed at a fixed sampling. It is shown that the synchronous exciter system can be achieved by the proposed controller using Characteristic Ratio Assignment.

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해상용 3 MW 영구자석형 동기발전기의 대안설계 (Alternative Design of 3MW Offshore PM Synchronous Generator)

  • 김동언;이홍기;한홍식;정영규;서형석;정진화;임민수;곽승근;오만수;최준혁
    • 한국신재생에너지학회:학술대회논문집
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    • pp.274-277
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    • 2008
  • Pohang Wind Energy Research Center (PoWER-C) is developing a 3 MW Radial Flux Permanent Magnet (RFPM) Synchronous Generator for offshore Wind Energy Converter (WEC). The blade rotor rpm is 15.7 and the gear ratio is set to be 92.93. The nominal generator rpm at the rated load is about 1459. Baseline design with surface mounted PM magnets are completed. However, there is some concern about the excessive eddy current heating in the magnets. To alleviate this problem, another design with embedded magnet is going on. With embedded magnets, the generator length should be increased to compensate the increased flux leakage. But the field fluctuation in the magnets due to the slots are greatly reduced. This means less eddy currents and lower magnet operating temperature. In this report, engineering efforts for embedded rotor is presented.

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